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Jelly Ear
Auricularia auricula-judae, known as the Jew's ear, jelly ear or by a number of other common names, is a species of edible Auriculariales fungus found worldwide. The fruiting body is distinguished by its noticeably ear-like shape and brown colouration; it grows upon wood, especially elder. Its specific epithet is derived from the belief that Judas Iscariot hanged himself from an elder tree; the common name "Judas's ear" eventually became "Jew's ear", while today "jelly ear" or other names are sometimes used. The mushroom can be found throughout the year in temperate regions worldwide, where it grows upon both dead and living wood. Although it is not regarded as a choice edible mushroom in the west, it has long been popular in China, to the extent that Australia exported large volumes of the mushroom to China in the early twentieth century. While not widely consumed in the west, A. auricula-judae was used in folk medicine as recently as the 19th century for complaints including sore throats, sore eyes and jaundice, and as an astringent. Today, the mushroom is a popular ingredient in many Chinese dishes, such as hot and sour soup, and also used in Chinese medicine. It is also used in Ghana, as a blood tonic. Modern research into possible medical applications have variously concluded that A. auricula-judae has antitumour, hypoglycemic, anticoagulant and cholesterol-lowering properties. Description The fruit body of A. auricula-judae is normally 3 to 8 centimetres (1.2 to 3.1 in) across, but can be as much as 12 centimetres (4.7 in). It is distinctively shaped, typically being reminiscent of a floppy ear, though the fruit bodies can also be cup-shaped. It is normally attached to the substrate by the back surface of the cup, though there can also be a rudimentary stem. The species has a tough, gelatinous, elastic texture when fresh, but it dries hard and brittle. The outer surface is a bright reddish-tan-brown with a purplish hint, often covered in tiny, downy hairs of a grey colour. It can be smooth, as is typical of younger specimens, or undulating with folds and wrinkles. The colour becomes darker with age. The inner surface is a lighter grey-brown in colour and smooth. It is sometimes wrinkled, again with folds and wrinkles, and may have "veins", making it appear even more ear-like. Microscopic features The spores of A. auricula-judae are long and sausage shaped, ranging in size from 16 to 18 micrometres (μm) long by 6 to 8 μm thick. The spores themselves are white, cream or yellowish, and are hyaline. The spores can sometimes be seen in a whitish mass on the underside of the fruit body. The species has elongated cylindrical basidia with three transverse septa (internal cross-walls dividing the hyphae). Hairs on the fruit body are from 85 to 100 μm in length, and 5 to 6 μm in diametre. They are hyaline, lack a central strand and have rounded tips. They do not grow in dense tufts. Habitat, ecology and distribution Auricularia auricula-judae grows upon the wood of deciduous trees and shrubs, favouring elder. In up to 90% of cases, the mushroom is found on elder, but it is often incorrectly assumed to grow exclusively on elder. It has also been recorded on Acer pseudoplatanus (known in the United Kingdom as sycamore), beech, ash, spindle, and in one particular case, the sycamore draining board of an old sink in Hatton Garden. In Australia, it is found in Eucalyptus woodland and rainforests; in the rainforests, it can grow in very large colonies on fallen logs. It favours older branches, where it feeds as a saprophyte (on dead wood) or a weak parasite (on living wood), and it causes white rot. Commonly growing solitarily, it can also be gregarious (in a group) or caespitose (in a tuft). Spores are ejected from the underside of the fruit bodies with as many as several hundred thousand an hour, and the high rate continues when the bodies have been significantly dried. Even when they have lost some 90% of their weight through dehydration, the bodies continue to release a small number of spores. It is found all year, but is most common in autumn. It is widespread throughout temperate and sub-tropical zones worldwide, and can be found across Europe, North America, Asia, Australia, South America and Africa. There has been some debate about the appearance of the species in the tropics; while it has been frequently reported there, Bernard Lowy, in an article on Auricularia, said that "of the specimens I have examined, none could be assigned here". Category:Fungi Category:Other Fungi